🚤 Boat Fuel Consumption Calculator

Estimate boat fuel use per hour and per distance. Enter power, fuel type, speed, and trip to get L/h, GPH, total fuel, cost, and range.

Last updated: 2025-10-21 — Compiled and reviewed by Calvin (Automotive Research, FreeCalculators.app)

Results

Enter inputs and click Calculate to see results.

Speed vs Fuel per NM

Chart samples six speeds around your input (±20%) and estimates liters per nautical mile.

Methodology (formulas)

Gasoline base: L/h = hp × 0.24 × load × sea × hull × engine. Diesel base: hp × 0.20 × load × sea × hull × engine.

Per distance: L/NM = (L/h) ÷ speed(knots). Also show L/mi and L/km.

Total fuel: distance × fuel per distance. Cost uses price per liter or gallon.

Frequently Asked Questions

How do I calculate boat fuel consumption?

You can estimate boat fuel consumption using the formula: Fuel (L/h) ≈ Engine horsepower × 0.24 (gasoline) or 0.20 (diesel) × load factor × sea condition factor. This gives an approximate hourly burn rate. For details, see the Wikipedia (DOE guide).

What units are used to measure boat fuel consumption?

The most common units are L/h (liters per hour) and GPH (gallons per hour). For trip planning, many skippers also convert results to L/NM (liters per nautical mile) or MPG (miles per gallon). You can reference conversion values on Wikipedia's fuel efficiency units table (fuel efficiency).

What factors affect boat fuel efficiency?

Efficiency is influenced by load weight, sea conditions, hull shape, and propeller setup. Heavy load or rough water can increase consumption by 20–30%. For practical guidance, check NOAA's boating safety and weather guidelines (NOAA boating).

How can I reduce my boat's fuel consumption?

Maintain proper trim, keep the hull clean, and cruise at 70–80% of your maximum RPM for optimal fuel efficiency. Replacing damaged propellers and avoiding overloading also helps. For more fuel-saving practices, see BoatUS fuel efficiency tips (BoatUS tips).

How accurate is this calculator?

This calculator provides a theoretical estimate based on known engineering constants and test data. Actual fuel use can vary ±15–25% depending on conditions, engine maintenance, and prop setup. It's best to treat the result as a planning guide, not an exact figure.

Related Calculators

⛽

Mercury Fuel Consumption Calculator

Estimate Mercury outboard engine fuel consumption by model, RPM, speed, and conditions. Get L/h, GPH, fuel per mile, total fuel, and trip cost for FourStroke, Pro XS, Verado, SeaPro, and Racing.

Try it now

⚙️

2 Stroke Oil Mix Calculator

Calculate the perfect oil-to-gas ratio for your 2-stroke engine. Supports 50:1, 40:1, 32:1 ratios for chainsaws, outboards, dirt bikes, and more.